Preventive medicine consists of measures taken to reduce the risk of diseases, including avoiding smoking, performing physical exercises and following prudent dietary recommendations.
Recently, there is an increasing awareness that food may be either harmful or beneficial to health. This is based in part on a growing scientific understanding of the disease-preventive properties of foods, and in particular certain food components, known as nutraceuticals, such as vitamins, omega-3 fatty acids, certain minerals and certain phytochemicals. Nutraceuticals are health-promoting bioactives. They have been associated with the prevention and/or treatment of disorders like cardio-vascular disease, cancer, hypertension, diabetes, osteoporosis, arthritis etc.
One way to increase the consumption of health promoting bioactives is to enrich foods and beverages that people normally consume with nutraceuticals. However, enriching foods with nutraceuticals may pose great challenges, especially when the nutraceuticals are poorly water-soluble, and are easily degradable.
The solubilization of hydrophobic health-promoting bioactives in clear drinks is highly sought by beverage producers to provide added value for the consumer, but it still poses tough challenges, particularly in shelf stable drinks. Most food grade surfactants, which may be used for the task are synthetic e.g. the Tween (polysorbate) series, and thus preclude an “all-natural ingredients” labeling. Other ways to enrich beverages with hydrophobic nutraceuticals, like gum Arabic, milk proteins, soybean proteins and Maillard reaction conjugates are either expensive, not always available, or are using allergenic components.
Clear drinks, which are consumed in large quantities, pose a particularly important challenge because of the difficulty of incorporating oil-soluble materials in a clear and stable aqueous system. The ideal vehicle for the task should be nano-sized to maintain transparency, preferably ≤100 nm, and comprised of only natural, generally regarded as safe and inexpensive food components, capable of solubilizing and protecting hydrophobic biologically active molecules in aqueous media while retaining sensory qualities, and promoting bioavailability of hydrophobic biologically active molecules. Very few solutions for these challenging requirements have been suggested and none has all the desired attributes.
Commercial pectins are often derived from citrus and apple pulps. These are characterized by high viscosity of low solids aqueous solutions and form gels in the presence of high solids sucrose solutions and/or calcium under mildly acidic conditions. Historically, commercial pectin production from sugar beet commenced in Europe during World War II but ceased when citrus and apple pulps again became available. Generally, sugar beet pectins were regarded as inferior and their function was enhanced by conversion to low ester pectinic acids which produce ionically crosslinked gels in the presence of polyvalent cations.
Spent sugar beet pulp consists largely of structural polysaccharide complexes associated with the primary cell wall of parenchymatous tissue. Subsequent extraction of spent beet pulp under hydrolytic conditions generates solubilized forms of the non-cellulosic components whose yield and chemical classification vary depending on the severity of hydrolysis condition and the specific extractive method employed.
Nanoencapsulation is a rapidly developing technology which has great potential to overcome solubility limitations, protect sensitive compounds from degradation during production and shelf-life, mask undesired off-flavors, and promote bioavailability of encapsulated nutraceuticals.
Vitamin D and omega 3 were chosen as model hydrophobic nutraceutical compounds. Vitamin D is a fat soluble vitamin that has great importance for calcium and phosphorus homeostasis. VD is also associated with cardiovascular health, cancer prevention, insulin sensitivity, regulation of immune function and decreased risk of autoimmune diseases. VD3 is synthesized in the skin upon exposure to ultraviolet type-B radiation. There are scarce natural dietary sources for VD, including certain fish oils and egg yolk. About 1 billion people worldwide are VD deficient or insufficient, mainly due to avoidance of sun exposure to prevent melanoma, the use of sunscreen which blocks VD synthesis and low dietary intake. Besides its low solubility in water, vitamin D is sensitive to low pH, oxidation and heat.
Omega 3 fatty acids show remarkable preventive-medicine activities: they reduce the risk of cardiovascular diseases and the metabolic syndrome, they lower blood pressure, serum cholesterol and triglyceride levels and they are considered to have antithrombotic, antiatherogenic and anti-inflammatory properties. However, omega 3 fatty acids and their ester forms have very low aqueous solubility, and very high sensitivity to oxidation, resulting in undesired odors and flavors.